When

CRPcys-XL binds GpVI, platelets are activated, leading to their aggregation [11] and [18]. Subsequently, SB431542 chemical structure a small set of triple-helical peptides containing primary sequence from collagen I was used to identify GFOGER as a motif that binds integrins α1β1 and α2β1 [12]. To cater for the possibility that cross-linking may similarly be required to support cellular activation via clustering of integrins, these and subsequent peptides, such as GFOGERcys (Table 1), generally included terminal Cys residues. We then synthesized two large sets of peptides (Toolkits) encompassing the entire triple-helical domains of the homotrimeric collagens II and III in 56 and 57 peptides, respectively [3] and [14]. We use three examples of Toolkit peptides in this paper (Table 1). With the aid of their helix-inducing host sequence, all these peptides fold to form canonical collagen triple helices of similar stability to native collagen [23]. Toolkit peptides have facilitated the systematic mapping of receptors [3], [14] and [33] and structural binding proteins [3], [15] and [16] onto collagens II and III. GW786034 manufacturer Applications for triple-helical peptides may be developed in several ways: the Toolkit approach might be applied to collagen I using heterotrimeric peptides [5], [25] and [28]. Collagen-mimetic peptides are used in biomaterials [24] and may also

have diagnostic applications. For example, the identification of a site that bound von Willebrand factor

(VWF) using the Toolkits [16] enabled the development of a defined, collagen-mimetic peptide mixture of VWF-, GpVI- and integrin-binding peptides that can support thrombus formation under shear conditions [22], Carnitine palmitoyltransferase II valuable for diagnostic purposes. Although the heterogeneity of these peptides is increased by random oxidation of their terminal cysteine residues (Fig. 1), the latter provide a valuable means of introducing higher-order structure through chemical crosslinking. Their role has not been investigated in any depth, and forms an important focus of this report. Here, we provide a framework for investigating cross-linked polymeric collagen peptides that complements work on fibril-forming collagen peptides where cysteine aids helix stabilization [13] and [21]. We also investigate the enhancement of adhesive properties conferred by the oxidation of cysteine upon storage, where the main use of peptides is to investigate cell–collagen interaction using solid-phase adhesion methodology. Peptides were synthesized as C-terminal amides on TentaGel R-Ram resin using an Applied Biosystems Pioneer peptide synthesizer as described previously [23]. Fractions containing homogeneous product were identified by analytical HPLC on an ACEphenyl300 (5 μm) column, characterized by MALDI and electrospray mass spectrometry, pooled and freeze-dried. Where applicable, biotin was coupled to the N-terminal group by addition of N-(biotinyloxy)succinimide (5 equiv.